1. Field of the Invention
The present invention is related to a touch calibration system and a method thereof, and more particularly related to a touch calibration system and a method thereof by using a counter which is set with a fixed count value.
2. Description of the Prior Art
Attending with the progress of technology, the development of network has led to a life full of electronic devices, of which the interface of touch control is the main trend. In order to make sure that the touch control on the electronic devices can run smoothly without trouble, a test for the touch circuit is necessary.
Please refer to FIGS. 1 and 2, wherein FIG. 1 is a block diagram of a conventional touch calibration system, and FIG. 2 is a diagram showing the oscillating wave of the conventional art. As shown, in the existed touch calibration system PA1, a waveform generation module PA12 is electrically connected to a touch pad PA11, a counter PA13 is electrically connected to the waveform generation module PA12, a timer PA14 is electrically connected to the counter PA13 and set with a fixed timer value, and a data computing module PA15 is electrically connected to the counter PA13.
When doing the calibration by using the above mentioned technology, the touch pad PA11 is untouched and the waveform generation module PA12 generates the oscillating waves 100, 200, 300. Concretely speaking, the above mentioned oscillating waves 100, 200, 300 are defined as being composed of an upward section and a downward section. That is, the section between time t0 and t2 in FIG. 2 is the oscillating wave 100, the section between time t2 and t4 is the oscillating wave 200, and the section between time t4 and t6 is the oscillating wave 300. During the calibration, the timer PA14 measures the above mentioned fixed timer value (e.g. 1 ms) and triggers the counter PA13 to count the number of the generated oscillating waves within the fixed timer value when the measured time equals to the fixed timer value. For example, as the fixed time value is the time period between time t0 and t4 in FIG. 2 (i.e. t4 minus t0), then, the counter number would be two, i.e. oscillating waves 100 and 200. Then, the computed data (such as the waveform showing the relationship between the counted number and time) would be transmitted to the data computing module PA15 for computing a result with a better signal to noise ratio (SNR).
However, in general, for the calibration method in which the timer PA14 is set to measure a fixed time value, the data computing module PA15 needs to conduct the switches (not shown) in the waveform generating module PA12 repeatedly to choose the number of constant currents (not shown) for accessing a better signal to noise ratio. Because the calibration method needs to run the test repeatedly, it would spend lots of time and thus is not cost-efficient.
In addition, when determining the existence of a touch, the applicable algorithm of the data computing module PA15 is also restricted by the above mentioned calibration method. Because the determination is based on the number counted by the counter, a complicated method should be used. For example, the data computing module PA15 in practice may use a filter with various filtering coefficients (e.g. eight different filtering coefficients) for computing the counted data from the counter PA13. Such determination would be quite time-consuming and thus there exists a need to improve the technology in present.